thromboxane-a2 and Leiomyoma

An increased risk of cardiovascular disease has been found in postmenopausal women in comparison to premenopausal women. The aim of this study was to investigate platelet function, blood clotting and plasma lipid levels in 12 women with a condition of hypoestrogenism, similar to the postmenopausal status induced by treatment with the GnRH analogue buserelin for uterine leiomyoma. Platelet aggregation in whole blood and platelet-rich plasma (PRP), serum thromboxane (TX) B2 production, fibrinopeptide A (FPA) plasma levels and plasma lipid pattern were measured before and after 13 weeks of buserelin treatment. No changes of platelet aggregability were found either in whole blood or PRP. Serum TXB2 generation increased significantly after 13 weeks of therapy (p less than 0.001). No signs of increased thrombin generation were found, as indicated by unchanged FPA plasma levels. Total cholesterol plasma levels were found increased after 13 weeks, LDL cholesterol levels showed a tendency to increase although not significantly. HDL cholesterol and triglyceride concentrations were unaffected. The changes of arachidonic acid metabolism and lipid pattern suggest that buserelin treatment may induce a condition of increased thrombotic risk even if the lack of enhanced thrombin generation and increased platelet aggregability indicates that no blood clotting activation occurs.

Topics: Adult; Blood Coagulation; Blood Platelets; Buserelin; Female; Gonadal Steroid Hormones; Humans; Leiomyoma; Lipids; Menopause; Middle Aged; Thromboxane A2; Uterine Neoplasms

The release of 6-keto-prostaglandin F1 alpha(6-keto-PGF1 alpha), a metabolite of prostacyclin (PGI2) and thromboxane B2 (TxB2), a metabolite of thromboxane A2 (TxA2), was estimated in endometrial biopsies taken from 12 menorrhagic and 12 healthy women during the luteal phase of the cycle. The releases of 6-keto-PGF1 alpha and TxB2 were normal, but the ratio TxB2/6-keto-PGF1 alpha was inversely related to menstrual blood loss in women with measured menstrual blood loss exceeding 70 ml. In the second part of the study, 24 women with excessive menstrual bleeding (13 with primary menorrhagia, 10 with uterine fibromyomas, one with haemostatic factor VIII deficiency) were treated at random with ibuprofen (600 mg/day and 1200 mg/day) and with a placebo. Ibuprofen 1200 mg/day reduced (P less than 0.01) median blood loss from 146 ml (range 71-374 ml) to 110 ml (30-288 ml) in primary menorrhagia but had no effect on blood loss in women with uterine fibroids and factor VIII deficiency. Blood loss was normal in six women and was not affected by ibuprofen. Thus, our data suggest that there is a PGI2 dominance in the endometrium of patients with menorrhagia. In addition, primary, but neither fibromyoma nor coagulation defect-associated menorrhagia, can be treated by ibuprofen.

Topics: Adult; Clinical Trials as Topic; Double-Blind Method; Endometrium; Epoprostenol; Female; Humans; Ibuprofen; Leiomyoma; Menorrhagia; Middle Aged; Random Allocation; Thromboxane A2; Uterine Neoplasms

To study the role of prostacyclin (PGI2) and thromboxane A2 (TxA2) in uterine tumors, pieces of endometrial cancer (n = 12) and leiomyomas (n = 12) were incubated in vitro, and the productions of 6-keto-prostaglandin F1a (6-keto-PGF1a, a hydration product of PGI2) and thromboxane B2 (TxB2, a hydration product of TxA2), measured by radioimmunoassay, were compared to those of corresponding healthy tissues. The production of 6-keto-PGF1a by endometrial cancer (20.8; 15.1-85.0 ng/mg protein/min, median and interquartile range), by healthy endometrium (25.5; 10.0-55.0), by healthy myometrium (34.9; 25.0-59.9) and by leiomyoma (20.3; 10.2-45.1) was similar. The production of TxB2 was increased by endometrial cancer (55.5; 10.5-155.2, p less than 0.02) in comparison with endometrium (9.8; 4.3-35.1), myometrium (3.8; 2.1-8.0) and leiomyoma (1.9; 1.0-3.8). The 6-keto-PGF1a/TxB2 ratio in endometrial cancer (0.9; 0.3-1.5) was smaller (p less than 0.02) than that in healthy endometrium (3.3; 1.9-4.8). Thus, TxA2 may be a factor in endometrial cancer.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Aged; Aged, 80 and over; Epoprostenol; Female; Humans; In Vitro Techniques; Leiomyoma; Middle Aged; Thromboxane A2; Thromboxane B2; Uterine Neoplasms